Apparently they don't necessarily disagree with the total loss claimed.

Looks like six teams are responsible for shutting down the league this season. I wonder who they are?

Much more than 6. There are probably 6 profit making teams. That means 24 teams are losing money, 6 some more than the 18 other losers. If you believe the NHL those 18 lost about $100m between them. There is about $50m difference between the NHLPA and the NHL which is probably the profit made by the money making clubs. Maybe the NHLPA is write and those 18 clubs only lost $50m. Doesn't matter at least 18 clubs are losing enough money to be serious, probably closer to 24.

That isn't even taking into account the owners would want to see some profit on their investments, a minimum of the 5% they could have gotten from a bank or bond. At the end of the day, 80% of the teams at or below breakeven is BAD.